CN87203854U

CN87203854U - Centrifugal pump impeller capable of automatic balancing axial force

Info

Publication number: CN87203854U
Application number: CN 87203854
Authority: CN
Inventors: 郭宝权
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-21
Filing date: 1987-03-21
Publication date: 1987-12-26

Abstract

The utility model discloses a centrifugal pump impeller capable of automatic balancing axial force, which relates to the centrifugal pump, in particular to the impeller of the multi-stage centrifugal pump. Since the impeller of the multi-stage centrifugal pump is arranged on a pump shaft through the sliding fit, and the internal diameter phi 2 of the outlet sealing ring is k times (K is the empirical coefficient which is greater than 1) of the internal diameter phi 1 of the inlet sealing ring. The stopper end surfaces of the upper and the lower cover plates are designed with an upper anti-thrust flange surface and a lower anti-thrust flange surface, and a balance hole is arranged on the upper anti-thrust surface. A strengthening tile with the anti-thrust surface is inserted on the flow guiding casing between the flow guiding casing and the pump shaft, and a balancing chamber is communicated by the clearance between the strengthening tile and the flange of the upper anti-thrust flange and the balance hole. Under any operating condition, the impeller of the multi-stage centrifugal pump can totally automatically balance the axial force.

Description

Centrifugal pump impeller capable of automatic balancing axial force

The utility model relates to centrifugal pump, especially the impeller of multistage centrifugal pump.

Because well has advantages such as water displacement is big, efficient is high, floor space is little, noise is low, working service is convenient with Submerged Motor Pumps, use increasingly extensively, replaced borehole shaft drivenpump and single-stage ground centrifugal pump gradually.Especially surpass under 200 meters the high-lift condition at well depth, the deep-well Submerged Motor Pumps is main high efficiency water lift.

Submersible pump is generally multistage centrifugal pump.Each of pump grade all is made up of an identical receded disk impeller and a blower inlet casing.The submersible electric motor that is positioned at foot drives the pump shaft high speed rotating by coupling, drives the impeller high speed rotating at different levels that are fixed on the pump shaft, and the current by impeller are thrown away at a high speed by impeller, enter the next stage impeller from impeller outlet through blower inlet casing.Whenever just once pressurized by one-level, be discharged to the well head of gushing out the lifting pipe from outlet at last.

The main structure of this multistage centrifugal submersible pump part is shown in figure one, by impeller (1), blower inlet casing (2), set upright bearing shell (3), inlet seal ring (4), exit seal ring (5), axle sleeve (6), pump shaft (7), flat key (8) etc. and form.

This centrifugal submersible pumps owing to the effect of water pressure and impact of water, must produce the P that makes a concerted effort of downward axial water pressure power in operation process ₁, current recoil force P ₂With impeller weight power P ₃P wherein ₁Be owing to act on the impeller, the water pressure difference of lower cover plate forms, and when pump ran well, this power was more much bigger than other two active forces usually, it is directed downwards, only pump during in low lift, the operation of big flow this power just can be less than the current direction of impeller on recoil force P ₂(F=P makes a concerted effort with joint efforts to make impeller be subjected to one ₁-P ₂+ P ₃).

Above-mentioned three power are calculated with following formula respectively.

P ₁＝KHirπ（rω－rh）

P ₂＝＝ ^Qt _gγ（Um－UmCOSλ）

P ₃＝mg

Wherein:

P ₁-act on a water pressure on the impeller to make a concerted effort, be directed downwards (kgf)

P ₂-current are to the recoil force of impeller, and direction is with P opposite (kgf)

P ₃-impeller weight (kilogram force)

Hi-single-stage lift (rice)

γ-fluid density (kilogram/rice ³)

γ ω-impeller inlet seal ring radius (rice)

γ h-impeller hub radius (rice)

K-experiment coefficient (ns is relevant with comparand, K=0.6～0.8 when ns=40～200)

Qt-is by the flow (rice of impeller ³/ hour)

Um-liquid enters the axial component velocity before the impeller blade.

The Um-flow of liquid goes out the axial plane component of velocity behind the impeller.

λ ₂-axial plane component of velocity Um and impeller axis angular separation are (for radial flow impeller λ ₂P in the time of=90 ° ₂= ^Qt _gγ Um)

M=impeller quality (kilogram)

G-gravity accleration constant is 9.81 meter per seconds

Act on the axial force on it at present in the pump operation process, the following dual mode balance of general employing: (one) establishes plane thrust dish (for water-filling wet diving motor) or radial antifriction bearing (for oil-filled submersible motor) in motor lower portion, and the axial force that acts on the impellers at different levels passes on thrust button or the rolling bearing along axle.This method for the lower pump axial force of lift less than 500kg(112 " well pump) still can use reluctantly, but this also to be pump really break down and the one of the main reasons that influences working life.And higher when lift, axial force is during greater than 500kg, for Water-filled Type Submersible Motors just extremely difficulty born this power, even oil-filled submersible motor, its life-span also shortens to some extent.

(2) be the mode that adopts the impeller double seal ring shown in figure one and open equalizing orifice.On the forward and backward cover plate of impeller, respectively add a seal ring (4,5) exactly respectively.And on back shroud, beat several equalizing orifices (K), counter balance pocket (A) is communicated with impeller inlet.General import and export seal ring is made inner diameter and is equated, can make the downward axial force of impeller reduce by 2/3rds like this.Other 1/3rd axial forces still need to be born by the motor thrust button.Still can be for this power of high-head pump greatly to the degree that is difficult to bear.For this reason, there is the people that impeller outlet seal ring inner diameter is strengthened, makes it greater than inlet seal ring inner diameter certain value, thereby can make impeller under nominal situation, be in the state of axial force complete equilibrium.Yet, when being in, pump off-design operating mode can produce make a concerted effort (F) that a promotion impeller makes progress when big flow moves inevitably, this power makes in the vane rotor system and scurries, and causes thrust button wearing and tearing on wearing and tearing of impeller upper cover plate or the motor, and the pump running is played pendulum.

The utility model is intended to improve impeller, with balancing axial thrust, when no matter pump is worked under any operating mode or under high-lift, impeller itself can both its axial force of balance, and can under big range of flow operating mode, be in state of suspension up and down, and fundamentally eliminate the various wearing and tearing that cause owing to axial force, prolong the life-span of impeller, reduce the mechanical friction energy consumption simultaneously, improve unit efficiency.

The utility model is to realize above-mentioned purpose like this: (referring to Fig. 2) (one) is designed to the structure that can be free to slide along pump shaft (7) to impeller (1), and impeller is contained on the pump shaft to be slidingly matched).

(2) with the internal diameter φ of the exit seal ring (5) on the impeller upper cover plate ₂Be increased to internal diameter φ for the inlet seal ring (4) on the lower cover plate ₁K (be φ doubly ₂=K φ ₁, K is the empirical coefficient greater than 1, to 10 " and well submersible pump K equals 1.3).

(3) design has upper and lower thrust flanges face (M, N) on the upper and lower cover plate seam end face of impeller, and is equipped with some equalizing orifices (K) on last thrust flanges face (M).

(4) centrilizing tile that has thrust surface (B) (9) that is inlaid on the blower inlet casing is set between blower inlet casing and pump shaft, it is that the high-abrasive material of low hardness is made in using.Counter balance pocket (A) and impeller cavity are by thrust surface (B) and the gap (h) between the impeller thrust flanges face (M) and equalizing orifice (K) communication of centrilizing tile (9).

Like this, enter the flow liquid of counter balance pocket (A), when entering impeller (1) import, thrust surface (B) and the gap (h) between the last thrust flanges face (M) and equalizing orifice (K) of the necessary centrilizing tile of process earlier.When the work of design declared working condition point, impeller is in friction-free quick condition on pump shaft, and gap (h) is a definite value (h ₀) (h ₀=(nd)/(5D), and d-equalizing orifice diameter, the number of n-equalizing orifice, the circular diameter of D-equalizing orifice center circular arc of living in), the pressure in the Seal cage (A) also is a definite value.

Impeller is in the work of design conditions point, if when impeller (1) in actual gap greater than h ₀Non-design attitude the time, the pressure in the Seal cage (A) reduces, impeller moves up under an effect of upwards making a concerted effort; Along with reducing of gap (h), the pressure in the Seal cage (A) rises, and upward axis reduces to making a concerted effort, until the vanishing of making a concerted effort.Otherwise, when impeller is in actual gap less than h.The time, axially make a concerted effort downwards, push away under the impeller, until h=h ₀Till.So the impeller of working under operating point always at automatic adjusted position, keeps best clearance h to equal h ₀State of suspension.

Under the special operation condition of certain big flow, low lift, can produce not very big axial making a concerted effort that makes progress, the last thrust surface (M) of impeller (1) is pressed on the thrust surface (B) of centrilizing tile (9).Yet this operating mode only just can occur when high-lift submersible pump starts, the time compole short, can not damage impeller.And under the low special operation condition of lift height, flow, axial force moves down impeller (1) downwards, and gap h is greater than h ₀, Seal cage (A) pressure reduces, axial force automatic balancing, and just impeller remains on gap h greater than h ₀A certain position, and impeller still is in state of suspension.

The drawing explanation:

Fig. 1 is for now using the blade wheel structure figure of pump.

Fig. 2 is blade wheel structure figure of the present utility model.Wherein: the 1-impeller; 2-blower inlet casing 3-guide bearing; 4-inlet seal ring; 5-exit seal ring; The 6-axle sleeve; The 7-pump shaft; The 8-flat key; The 9-centrilizing tile; M, N, B-thrust surface; The K-equalizing orifice.

Embodiment and effect:

I have made a mining deep well submerged pump model machine of 250QJK70-450/18 with such scheme, have designed 250QJK80 series specification product and 300QJK160-310/14 deep well submerged pump and the multistage water pump of DG type.Preliminary test according to model machine shows: the submersible pump of making 400 meters of lifts of this case case is feasible; Reduced the part of pump, removed pump shaft from and controlled, reduced required precision, thereby reduced cost to the amount of scurrying; Greatly reduce wearing and tearing, prolonged the life-span of pump, reduced the mechanical friction energy consumption and improved mechanical efficiency; Prolong the motor thrust button life-span, improved the reliability of pump; Improved the volumetric efficiency of pump.

Claims

1, a kind of centrifugal pump impeller that has the twoport seal ring and have equalizing orifice, of the present utility model being characterised in that: the centrifugal pump impeller of automatically balancing axial force is contained on the pump shaft to be slidingly matched, the internal diameter φ of the exit seal ring on the impeller upper cover plate ₂Be the inlet seal ring internal diameter φ on the lower cover plate ₁K doubly (K is the empirical coefficient greater than 1), design has upper and lower thrust flanges face on the upper and lower cover plate seam of impeller end face, on last thrust flanges face, be equipped with some equalizing orifices, be provided with a centrilizing tile that has thrust surface that is inlaid on the blower inlet casing between blower inlet casing and pump shaft, counter balance pocket and impeller cavity are to link up by gap between the thrust surface of centrilizing tile and the impeller thrust flanges face and equalizing orifice.